DESCRIPTION: The aims of this proposal are designed to provide a basic understanding of (1) the cellular basis of gammaHV68 latency; (2) the role of the immune system in regulating latency; (3) the viral gene products expressed during latency; and (4) the role of latency-associated gene products in latency and tumorigenesis. Aim 1. Characterization of gamma HV68 latency in immunocompetent and B cekk deficient mice. Aim 2. Regulation of gamma HV68 latency and gamma HV68-associated tumor developed by the immune system. Aim 3. Characterization of gamma HV 68 latency and tumor associated gene expression. Aim 4. Generation and analysis of gamma HV68 mutants in latency and tumor-associated genes.